Thumb() method not working

The CMS Questions
1

I’m in the process of updating and migrating a website on an old server that only supports PHP 7.4, and therefore Kirby 3.7.5 (since newer versions don’t work on PHP 7 anymore), and I noticed that the thumb() method isn’t working. (And before you complain: I need to get this running quickly and only after that I can and will make sure to move to a more modern server; it’s on shared hosting.)

I was originally developing the site locally with version 3.9.0 on PHP 8 and it generated thumbs without problems, but on that server I had to “downgrade” and the thumb() method fails. It says GD support is enabled. What could be the reason? Is it the Kirby version?

2

Could you please be more specific in describing what exactly is not working?

Is nothing at all created in the media folder?
Or the job files are created but no images?
Or there are images but they are not properly resized?

What kind of thumbs are you trying to create?
…

3

OK, sorry, the media folder is created and the images are showing up but they aren’t scaled according to the specifications, and it looks like they aren’t even cached.
Here’s the relevant part of the template:

<?php if($galerien = $page->children()->listed()): ?>
<ul class="galerien">
	<?php foreach($galerien as $galerie): ?>
	<li>
		<a href="<?= $galerie->url() ?>">
			<?php if($galerie->titelbild()->isNotEmpty()): ?>
			<?= $galerie->titelbild()->toFile()->thumb(['width' => 600, 'height' => 400, 'crop' => true]); ?>
			<?php else: ?>
			<?= $galerie->image()->thumb(['width'=>600, 'height' => 400, 'crop' => true]) ?>
			<?php endif; ?>
		</a>
		<div class="titel"><?= $galerie->title() ?></div>
		<?php if($galerie->text()->isNotEmpty()): ?>
		<div class="beschreibung"><?= $galerie->text()->kirbytext(); ?></div>
		<?php endif; ?>
	</li>
	<?php endforeach; ?>
</ul>
<?php endif; ?>

This is the page: Bilder – Blaskapelle Frischluftprojekt

I have a config setting like this:

'thumbs' => [
	'format' => 'webp',
	'presets' => [
		'quality' => 85,
		'width' => 600
	]
]

The JPEGs are converted to WEBP but are not resized and not cropped and not cached, it seems.